Acid-base implications of the Gibbs-Donnan effect during continuous veno-venous hemofiltration.

Background: This in-vitro and in-vivo study investigates the Gibbs-Donnan effect across the filter during continuous veno-venous hemofiltration (CVVH). In particular, we assessed its acid-base implications, applying the physical-chemical approach.

Methods: A prospective, single-center study was conducted using the PrismaMax machine (Baxter).

Effect of different sealing caps on the backflow of short-term dialysis catheters: A bench study.

Background: Needle-free connectors (NFCs) are recommended as closure systems for peripheral and central vascular catheters to reduce needlestick injuries and infections, while potentially reducing blood reflux. However, their performance in short-term dialysis catheters has never been evaluated. The aim of this study was to evaluate the backflow associated with two NFCs (Neutron™ and Tego™) compared to the standard closure.

Hyponatremia in Critically Ill Patients Due to Continuous Venovenous Hemofiltration With Diluted Sodium Citrate.

Continuous venovenous hemofiltration (CVVH) is frequently performed in critically ill patients using diluted citrate for regional anticoagulation. The impact of this renal replacement strategy on plasma sodium has not been evaluated yet. Our aim was therefore to assess the period prevalence of hyponatremia (sodium <135 mmol/L) during CVVH and discuss possible underlying mechanisms.

Quantitative Computed Tomography and Response to Pronation in COVID-19 ARDS.

Background: The use of prone position (PP) has been widespread during the COVID-19 pandemic. Whereas it has demonstrated benefits, including improved oxygenation and lung aeration, the factors influencing the response in terms of gas exchange to PP remain unclear. In particular, the association between baseline quantitative computed tomography (CT) scan results and gas exchange response to PP in invasively ventilated subjects with COVID-19 ARDS is unknown.

Quantifying pH-induced changes in plasma strong ion difference during experimental acidosis: clinical implications for base excess interpretation.

It is commonly assumed that changes in plasma strong ion difference (SID) result in equal changes in whole blood base excess (BE). However, at varying pH, albumin ionic-binding and transerythrocyte shifts alter the SID of plasma without affecting that of whole blood (SID), i.e.

Helmet continuous positive airway pressure for patients' transport using a single oxygen cylinder: A bench study.

Background: Continuous positive airway pressure (CPAP) is frequently used to treat patients with acute respiratory failure in out-of-hospital settings. Compared to a facemask, the helmet has many advantages for the patient but requires a minimum gas flow of 60 L/min to avoid CO rebreathing. The aim of the present bench study was to evaluate the performance of four Venturi devices, connected to a single oxygen cylinder, in delivering helmet-CPAP with clinically relevant gas flow, fraction of inspired oxygen (FiO) and positive end-expiratory pressure (PEEP) values.

Calcium-Citrate Anticoagulation during Continuous Renal Replacement Therapy in Patients with Metformin Intoxication: A Case Series, Mathematical Estimation of Citrate Accumulation, and Literature Review.

Introduction: Metformin intoxication causes lactic acidosis by inhibiting Krebs' cycle and oxidative phosphorylation. Continuous renal replacement therapy (CRRT) is recommended for metformin removal in critically ill patients. According to current guidelines, regional citrate anticoagulation (RCA) is the first-line strategy.

Combining the Physical-Chemical Approach with Standard Base Excess to Understand the Compensation of Respiratory Acid-Base Derangements: An Individual Participant Meta-analysis Approach to Data from Multiple Canine and Human Experiments.

Background: Several studies explored the interdependence between Paco2 and bicarbonate during respiratory acid-base derangements. The authors aimed to reframe the bicarbonate adaptation to respiratory disorders according to the physical-chemical approach, hypothesizing that (1) bicarbonate concentration during respiratory derangements is associated with strong ion difference; and (2) during acute respiratory disorders, strong ion difference changes are not associated with standard base excess.

Methods: This is an individual participant data meta-analysis from multiple canine and human experiments published up to April 29, 2021.

PEEP Titration Is Markedly Affected by Trunk Inclination in Mechanically Ventilated Patients with COVID-19 ARDS: A Physiologic, Cross-Over Study.

Background: Changing trunk inclination affects lung function in patients with ARDS. However, its impacts on PEEP titration remain unknown. The primary aim of this study was to assess, in mechanically ventilated patients with COVID-19 ARDS, the effects of trunk inclination on PEEP titration.

Flow generators for helmet CPAP: Which to prefer? A bench study.

Objective: To assess the different effect of filters' application during helmet-CPAP delivered with three different flow generators on the delivered fresh gas flow, FiO, and the noise level inside and outside the helmet.

Methods: In a bench study, three flow generators (air-oxygen blender, turbine ventilator and Venturi system) were used to generate two different gas flows (60 L/min and 80 L/min), with a fixed FiO at 0.6, to perform a helmet-CPAP on a manikin.

Non-carbonic buffer power of whole blood is increased in experimental metabolic acidosis: An study.

Non-carbonic buffer power (β) of blood is a pivotal concept in acid-base physiology as it is employed in several acid-base evaluation techniques, including the Davenport nomogram and the Van Slyke equation used for Base excess estimation in blood. So far, β has been assumed to be independent of metabolic acid-base status of blood, despite theoretical rationale for the contrary. In the current study, we used CO tonometry to assess β in blood samples from 10 healthy volunteers, simultaneously analyzing the electrolyte shifts across the red blood cell membrane as these shifts translate the action of intracellular non-carbonic buffers to plasma.

Cerebrospinal fluid and arterial acid-base equilibria in spontaneously breathing third-trimester pregnant women.

Background: Acid-base status in full-term pregnant women is characterised by hypocapnic alkalosis. Whether this respiratory alkalosis is primary or consequent to changes in CSF electrolytes is not clear.

Methods: We enrolled third-trimester pregnant women (pregnant group) and healthy, non-pregnant women of childbearing age (controls) undergoing spinal anaesthesia for Caesarean delivery and elective surgery, respectively.

Simulation-Based Medical Education and Training Enhance Anesthesia Residents' Proficiency in Erector Spinae Plane Block.

Background: Advances in regional anesthesia and pain management led to the advent of ultrasound-guided fascial plane blocks, which represent a new and promising route for the administration of local anesthetics. Both practical and theoretical knowledge of locoregional anesthesia are therefore becoming fundamental, requiring specific training programs for residents. Simulation-based medical education and training (SBET) has been recently applied to ultrasound-guided regional anesthesia (UGRA) with remarkable results.

The Effect of Filters on CPAP Delivery by Helmet.

Background: When helmet CPAP is performed using a Venturi system, filters are frequently interposed in the respiratory circuit to reduce noise within the helmet. The effect of the interposition of these filters on delivered fresh gas flow and the resulting F is currently unknown.

Methods: In a bench study, 2 different Venturi systems (WhisperFlow and Harol) were used to generate 3 different gas flow/F combinations (80 L/min-F 0.